Ключи к почвенной таксономии 2014

cm either from the mineral soil surface or from the top of an organic layer with andic soil properties, whichever is shallower; and

2.  On undried samples, a 1500 kPa water retention of 70 percent or more throughout a layer 35 cm or more thick within 100 cm of the mineral soil surface or of the top of an organic layer with andic soil properties, whichever is shallower.

Acrudoxic Hydric Melanudands

DHCF.  Other Melanudands that have a sum of extractable bases (by NH4OAc) plus 1N KCl-extractableAl3+ totaling less than 2.0 cmol(+)/kg in the fine-earth fraction of one or more horizons with a total thickness of 30 cm or more at a depth between 25 and 100 cm either from the mineral soil surface or from the top of an organic layer with andic soil properties, whichever is shallower.

Acrudoxic Melanudands

DHCG.  Other Melanudands that have both:

1.  More than 6.0 percent organic carbon and the colors of a mollic epipedon throughout a layer 50 cm or more thick within 60 cm of the mineral soil surface or of the top of an organic layer with andic soil properties, whichever is shallower; and

2.  A 1500 kPa water retention of less than 15 percent on air-dried samples and less than 30 percent on undried samples throughout one or more layers that have andic

soil properties and have a total thickness of 25 cm or more within 100 cm of the mineral soil surface or of the top of an organic layer with andic soil properties, whichever is shallower.

Pachic Vitric Melanudands

DHCH.  Other Melanudands that have a 1500 kPa water retention of less than 15 percent on air-dried samples and less than 30 percent on undried samples throughout one or more layers that have andic soil properties and have a total thickness of 25 cm or more within 100 cm of the mineral soil surface or of the top of an organic layer with andic soil properties, whichever is shallower.

Vitric Melanudands

DHCI.  Other Melanudands that have both:

1.  On undried samples, a 1500 kPa water retention of 70 percent or more throughout a layer 35 cm or more thick within 100 cm of the mineral soil surface or of the top of an organic layer with andic soil properties, whichever is shallower; and

2.  More than 6.0 percent organic carbon and the colors of

a mollic epipedon throughout a layer 50 cm or more thick within 60 cm of the mineral soil surface or of the top of an organic layer with andic soil properties, whichever is shallower.

Hydric Pachic Melanudands

DHCJ.  Other Melanudands that have more than 6.0 percent organic carbon and the colors of a mollic epipedon throughout a layer 50 cm or more thick within 60 cm of the mineral

soil surface or of the top of an organic layer with andic soil properties, whichever is shallower.

Pachic Melanudands

DHCK.  Other Melanudands that have, on undried samples, a 1500 kPa water retention of 70 percent or more throughout a layer 35 cm or more thick within 100 cm of the mineral soil surface or of the top of an organic layer with andic soil properties, whichever is shallower.

Hydric Melanudands

DHCL.  Other Melanudands that have, at a depth between

40 and 100 cm either from the mineral soil surface or from the top of an organic layer with andic soil properties, whichever is shallower, a layer 10 cm or more thick with more than 3.0 percent organic carbon and the colors of a mollic epipedon throughout, underlying one or more horizons with a total

thickness of 10 cm or more that have a color value, moist, 1 unit or more higher and an organic-carbon content 1 percent or more

(absolute) lower.

Thaptic Melanudands

DHCM.  Other Melanudands that have both:

1.  An argillic or kandic horizon within 125 cm of the mineral soil surface or of the top of an organic layer with andic soil properties, whichever is shallower; and

2.  A base saturation (by sum of cations) of less than 35 percent throughout the upper 50 cm of the argillic or kandic horizon.

Ultic Melanudands

DHCN.  Other Melanudands that have a sum of extractable bases (by NH4OAc) of more than 25.0 cmol(+)/kg in the fineearth fraction throughout one or more horizons with a total thickness of 15 cm or more at a depth between 25 and

75 cm either from the mineral soil surface or from the top of an organic layer with andic soil properties, whichever is shallower.

Eutric Melanudands

DHCO.  Other Melanudands.

Typic Melanudands

A N D

Placudands

Key to Subgroups

DHAA.  Placudands that have a lithic contact within 50 cm of the mineral soil surface or of the top of an organic layer that has andic soil properties, whichever is shallower.

Lithic Placudands

DHAB.  Other Placudands that have, in one or more horizons at a depth between 50 cm either from the mineral soil surface or from the top of an organic layer with andic soil properties, whichever is shallower, and the placic horizon, aquic conditions for some time in normal years (or artificial drainage) and one or more of the following:

1.  2 percent or more redox concentrations; or

2.  A color value, moist, of 4 or more and 50 percent or more chroma of 2 or less either in redox depletions on faces of peds or in the matrix if peds are absent; or

3.  Enough active ferrous iron to give a positive reaction to alpha,alpha-dipyridyl at a time when the soil is not being irrigated.

Aquic Placudands

DHAC.  Other Placudands that have a sum of extractable bases (by NH4OAc) plus 1N KCl-extractableAl3+ totaling less than 2.0 cmol(+)/kg in the fine-earth fraction of one or more horizons with a total thickness of 30 cm or more at a depth between 25 cm either from the mineral soil surface or from the top of an organic layer with andic soil properties, whichever is shallower, and the placic horizon.

Acrudoxic Placudands

DHAD.  Other Placudands that have, on undried samples, a 1500 kPa water retention of 70 percent or more throughout a layer 35 cm or more thick within 100 cm of the mineral soil surface or of the top of an organic layer with andic soil properties, whichever is shallower.

Hydric Placudands

DHAE.  Other Placudands.

Typic Placudands

Ustands

Key to Great Groups

DGA.  Ustands that have, in 75 percent or more of each pedon, a cemented horizon within 100 cm of the mineral soil surface or of the top of an organic layer with andic soil properties, whichever is shallower.

Durustands, p. 102

DGB.  Other Ustands.

Haplustands, p. 102

Durustands

Key to Subgroups

DGAA.  Durustands that have, in one or more horizons at a depth between 50 and 100 cm either from the mineral soil surface or from the top of an organic layer with andic soil properties, whichever is shallower, aquic conditions for some

time in normal years (or artificial drainage) and one or more of the following:

1.  2 percent or more redox concentrations; or

2.  A color value, moist, of 4 or more and 50 percent or more chroma of 2 or less either in redox depletions on faces of peds or in the matrix if peds are absent; or

3.  Enough active ferrous iron to give a positive reaction to alpha,alpha-dipyridyl at a time when the soil is not being irrigated.

Aquic Durustands

DGAB.  Other Durustands that have, at a depth between 25 and 100 cm either from the mineral soil surface or from the top of an organic layer with andic soil properties, whichever is shallower, a layer 10 cm or more thick with more than 3.0 percent organic carbon and the colors of a mollic epipedon throughout, underlying one or more horizons with a total

thickness of 10 cm or more that have a color value, moist, 1 unit or more higher and an organic-carbon content 1 percent or more

(absolute) lower.

Thaptic Durustands

DGAC.  Other Durustands that have a melanic, mollic, or umbric epipedon.

Humic Durustands

DGAD.  Other Durustands.

Typic Durustands

Haplustands

Key to Subgroups

DGBA.  Haplustands that have a lithic contact within 50 cm of the mineral soil surface or of the top of an organic layer with andic soil properties, whichever is shallower.

Lithic Haplustands

DGBB.  Other Haplustands that have, in one or more horizons at a depth between 50 and 100 cm either from the mineral

soil surface or from the top of an organic layer with andic soil properties, whichever is shallower, aquic conditions for some

time in normal years (or artificial drainage) and one or more of the following:

1.  2 percent or more redox concentrations; or

2.  A color value, moist, of 4 or more and 50 percent or more chroma of 2 or less either in redox depletions on faces of peds or in the matrix if peds are absent; or

3.  Enough active ferrous iron to give a positive reaction to alpha,alpha-dipyridyl at a time when the soil is not being irrigated.

Aquic Haplustands

DGBC.  Other Haplustands that have both:

1.  A sum of extractable bases (by NH4OAc) plus 1N KClextractable Al3+ totaling less than 15.0 cmol(+)/kg in the fine-earth fraction throughout one or more horizons with a total thickness of 60 cm or more within 75 cm of the mineral soil surface or of the top of an organic layer with andic soil properties, whichever is shallower; and

2.  A 1500 kPa water retention of less than 15 percent on air-dried samples and less than 30 percent on undried samples throughout one or more layers that have andic

soil properties and have a total thickness of 25 cm or more within 100 cm of the mineral soil surface or of the top of an organic layer with andic soil properties, whichever is shallower.

Dystric Vitric Haplustands

DGBD.  Other Haplustands that have a 1500 kPa water retention of less than 15 percent on air-dried samples and less than 30 percent on undried samples throughout one or more layers that have andic soil properties and have a total thickness of 25 cm or more within 100 cm of the mineral soil surface or of the top of an organic layer with andic soil properties, whichever is shallower.

Vitric Haplustands

DGBE.  Other Haplustands that have more than 6.0 percent organic carbon and the colors of a mollic epipedon throughout a layer 50 cm or more thick within 60 cm of the mineral

soil surface or of the top of an organic layer with andic soil properties, whichever is shallower.

Pachic Haplustands

DGBF.  Other Haplustands that have, at a depth between 25 and 100 cm either from the mineral soil surface or from the top of an organic layer with andic soil properties, whichever is shallower, a layer 10 cm or more thick with more than 3.0 percent organic carbon and the colors of a mollic epipedon throughout, underlying one or more horizons with a total

thickness of 10 cm or more that have a color value, moist, 1 unit

or more higher and an organic-carbon content 1 percent or more

(absolute) lower.

bases (by NH4OAc) plus 1N KCl-extractableAl3+ totaling less than 15.0 cmol(+)/kg in the fine-earth fraction throughout one or more horizons with a total thickness of 60 cm or more within 75 cm either of the mineral soil surface or of the top of an organic layer with andic soil properties, whichever is shallower.

Dystric Haplustands

DGBI.  Other Haplustands that have an oxic horizon within

125 cm of the mineral soil surface or of the top of an organic layer with andic soil properties, whichever is shallower.

Oxic Haplustands

DGBJ.  Other Haplustands that have both:

1.  An argillic or kandic horizon within 125 cm of the mineral soil surface or of the top of an organic layer with andic soil properties, whichever is shallower; and

2.  A base saturation (by sum of cations) of less than 35 percent throughout the upper 50 cm or throughout the entire argillic or kandic horizon if it is less than 50 cm thick.

Ultic Haplustands

DGBK.  Other Haplustands that have an argillic or kandic horizon within 125 cm of the mineral soil surface or of the top of an organic layer with andic soil properties, whichever is shallower.

Alfic Haplustands

DGBL.  Other Haplustands that have a melanic, mollic, or umbric epipedon.

Humic Haplustands

DGBM.  Other Haplustands.

Typic Haplustands

Vitrands

Key to Great Groups

DFA.  Vitrands that have an ustic soil moisture regime.

Ustivitrands, p. 104

A N D

DFB.  Other Vitrands.

Udivitrands, p. 104

Udivitrands

Key to Subgroups

DFBA.  Udivitrands that have a lithic contact within 50 cm of the mineral soil surface or of the top of an organic layer with andic soil properties, whichever is shallower.

Lithic Udivitrands

DFBB.  Other Udivitrands that have, in one or more horizons at a depth between 50 and 100 cm either from the mineral soil surface or from the top of an organic layer with andic soil properties, whichever is shallower, aquic conditions for some

time in normal years (or artificial drainage) and one or more of the following:

1.  2 percent or more redox concentrations; or

2.  A color value, moist, of 4 or more and 50 percent or more chroma of 2 or less either in redox depletions on faces of peds or in the matrix if peds are absent; or

3.  Enough active ferrous iron to give a positive reaction to alpha,alpha-dipyridyl at a time when the soil is not being irrigated.

Aquic Udivitrands

DFBC.  Other Udivitrands that are saturated with water within

100 cm of the mineral soil surface in normal years for either or both:

1.  20 or more consecutive days; or

2.  30 or more cumulative days.

Oxyaquic Udivitrands

DFBD.  Other Udivitrands that have, at a depth between 25 and 100 cm either from the mineral soil surface or from the top of an organic layer with andic soil properties, whichever is shallower, a layer 10 cm or more thick with more than 3.0 percent organic carbon and the colors of a mollic epipedon throughout, underlying one or more horizons with a total

thickness of 10 cm or more that have a color value, moist, 1 unit or more higher and an organic-carbon content 1 percent or more

(absolute) lower.

Thaptic Udivitrands

DFBE.  Other Udivitrands that have both:

1.  An argillic or kandic horizon within 125 cm of the mineral soil surface or of the top of an organic layer with andic soil properties, whichever is shallower; and

2.  A base saturation (by sum of cations) of less than 35

percent throughout the upper 50 cm of the argillic or kandic horizon.

Ultic Udivitrands

DFBF.  Other Udivitrands that have an argillic or kandic horizon within 125 cm of the mineral soil surface or of the top of an organic layer with andic soil properties, whichever is shallower.

Alfic Udivitrands

DFBG.  Other Udivitrands that have a melanic, mollic, or umbric epipedon.

Humic Udivitrands

DFBH.  Other Udivitrands.

Typic Udivitrands

Ustivitrands

Key to Subgroups

DFAA.  Ustivitrands that have a lithic contact within 50 cm of the mineral soil surface or of the top of an organic layer with andic soil properties, whichever is shallower.

Lithic Ustivitrands

DFAB.  Other Ustivitrands that have, in one or more horizons at a depth between 50 and 100 cm either from the mineral

soil surface or from the top of an organic layer with andic soil properties, whichever is shallower, aquic conditions for some time in normal years (or artificial drainage) and one or more of the following:

1.  2 percent or more redox concentrations; or

2.  A color value, moist, of 4 or more and 50 percent or more chroma of 2 or less either in redox depletions on faces of peds or in the matrix if peds are absent; or

3.  Enough active ferrous iron to give a positive reaction to alpha,alpha-dipyridyl at a time when the soil is not being irrigated.

Aquic Ustivitrands

DFAC.  Other Ustivitrands that have, at a depth between 25 and 100 cm either from the mineral soil surface or from the top of an organic layer with andic soil properties, whichever is shallower, a layer 10 cm or more thick with more than 3.0 percent organic carbon and the colors of a mollic epipedon throughout, underlying one or more horizons with a total

thickness of 10 cm or more that have a color value, moist, 1 unit or more higher and an organic-carbon content 1 percent or more

(absolute) lower.

Thaptic Ustivitrands

DFAD.  Other Ustivitrands that have a calcic horizon within

125 cm of the soil surface or of the top of an organic layer with andic soil properties, whichever is shallower.

Calcic Ustivitrands

DFAE.  Other Ustivitrands that have a melanic, mollic, or umbric epipedon.

Humic Ustivitrands

DFAF.  Other Ustivitrands.

Typic Ustivitrands

Xerands

Key to Great Groups

DEA.  Xerands that have a 1500 kPa water retention of less than 15 percent on air-dried samples and less than 30 percent on undried samples throughout 60 percent or more of the thickness either:

1.  Within 60 cm of the mineral soil surface or of the top of an organic layer with andic soil properties, whichever is shallower, if there is no densic, lithic, or paralithic contact, duripan, or petrocalcic horizon within that depth; or

2.  Between the mineral soil surface or the top of an organic layer with andic soil properties, whichever is shallower,

and a densic, lithic, or paralithic contact, a duripan, or a petrocalcic horizon.

Haploxerands

Key to Subgroups

DECA.  Haploxerands that have a lithic contact within 50 cm of the mineral soil surface or of the top of an organic layer with andic soil properties, whichever is shallower.

Lithic Haploxerands

DECB.  Other Haploxerands that have, in one or more horizons at a depth between 50 and 100 cm either from the mineral soil surface or from the top of an organic layer with andic soil properties, whichever is shallower, aquic conditions for some time in normal years (or artificial drainage) and one or more of the following:

1.  2 percent or more redox concentrations; or

2.  A color value, moist, of 4 or more and 50 percent or

more chroma of 2 or less either in redox depletions on faces of peds or in the matrix if peds are absent; or

3.  Enough active ferrous iron to give a positive reaction to alpha,alpha-dipyridyl at a time when the soil is not being irrigated.

Aquic Haploxerands

DECC.  Other Haploxerands that have, at a depth between 25 and 100 cm from the mineral soil surface or from the top of an organic layer with andic soil properties, whichever is shallower, a layer 10 cm or more thick with more than 3.0 percent organic carbon and the colors of a mollic epipedon throughout, underlying one or more horizons with a total thickness of 10

cm or more that have a color value, moist, 1 unit or more higher and an organic-carbon content 1 percent or more (absolute) lower.

Thaptic Haploxerands

DECD.  Other Haploxerands that have a calcic horizon within

125 cm of the mineral soil surface.

Calcic Haploxerands

DECE.  Other Haploxerands that have both:

1.  An argillic or kandic horizon within 125 cm of the mineral soil surface or of the top of an organic layer with andic soil properties, whichever is shallower; and

2.  A base saturation (by sum of cations) of less than 35 percent throughout the upper 50 cm of the argillic or kandic horizon.

Ultic Haploxerands

DECF.  Other Haploxerands that have both: 1.  A mollic or umbric epipedon; and

2.  An argillic or kandic horizon within 125 cm of the mineral soil surface or of the top of an organic layer with andic soil properties, whichever is shallower.

Alfic Humic Haploxerands

DECG.  Other Haploxerands that have an argillic or kandic horizon within 125 cm of the mineral soil surface or of the top of an organic layer with andic soil properties, whichever is shallower.

Alfic Haploxerands

DECH.  Other Haploxerands that have a mollic or umbric epipedon.

Humic Haploxerands

DECI.  Other Haploxerands.

Typic Haploxerands

A N D

Melanoxerands

Key to Subgroups

DEBA.  Melanoxerands that have more than 6.0 percent organic carbon and the colors of a mollic epipedon throughout a layer 50 cm or more thick within 60 cm of the mineral

soil surface or of the top of an organic layer with andic soil properties, whichever is shallower.

Pachic Melanoxerands

DEBB.  Other Melanoxerands.

Typic Melanoxerands

Vitrixerands

Key to Subgroups

DEAA.  Vitrixerands that have a lithic contact within 50 cm of the mineral soil surface or of the top of an organic layer with andic soil properties, whichever is shallower.

Lithic Vitrixerands

DEAB.  Other Vitrixerands that have, in one or more horizons at a depth between 50 and 100 cm either from the mineral

soil surface or from the top of an organic layer with andic soil properties, whichever is shallower, aquic conditions for some time in normal years (or artificial drainage) and one or more of the following:

1.  2 percent or more redox concentrations; or

2.  A color value, moist, of 4 or more and 50 percent or more chroma of 2 or less either in redox depletions on faces of peds or in the matrix if peds are absent; or

organic layer with andic soil properties, whichever is shallower, a layer 10 cm or more thick with more than 3.0 percent organic carbon and the colors of a mollic epipedon throughout, underlying one or more horizons with a total thickness of 10

cm or more that have a color value, moist, 1 unit or more higher and an organic-carbon content 1 percent or more (absolute) lower.

Thaptic Vitrixerands

DEAD.  Other Vitrixerands that have both:

1.  A melanic, mollic, or umbric epipedon; and

2.  An argillic or kandic horizon within 125 cm of the mineral soil surface or of the top of an organic layer with andic soil properties, whichever is shallower.

Alfic Humic Vitrixerands

DEAE.  Other Vitrixerands that have both:

1.  An argillic or kandic horizon within 125 cm of the mineral soil surface or of the top of an organic layer with andic soil properties, whichever is shallower; and

2.  A base saturation (by sum of cations) of less than 35 percent throughout the upper 50 cm or throughout the entire argillic or kandic horizon if it is less than 50 cm thick.

Ultic Vitrixerands

DEAF.  Other Vitrixerands that have an argillic or kandic horizon within 125 cm of the mineral soil surface or of the top of an organic layer with andic soil properties, whichever is shallower.

Alfic Vitrixerands

3.  Enough active ferrous iron to give a positive reaction to alpha,alpha-dipyridyl at a time when the soil is not being irrigated.

Aquic Vitrixerands

DEAC.  Other Vitrixerands that have, at a depth between 25 and 100 cm from the mineral soil surface or from the top of an

Key to Suborders

GA.  Aridisols that have a cryic soil temperature regime.

Cryids, p. 122

and do not have a petrocalcic horizon within 100 cm of the soil surface.

Argids

Key to Great Groups

GEA.  Argids that have a duripan or a petrocalcic or petrogypsic horizon within 150 cm of the soil surface.

Petroargids, p. 115

paralithic contact within 50 cm of the soil surface and have either:

1.  An argillic horizon that has 35 percent or more noncarbonate clay throughout one or more subhorizons in its upper part, and one or both of the following:

a.  A clay increase of 15 percent or more (absolute, in the fine-earth fraction) within a vertical distance of 2.5 cm either within the argillic horizon or at its upper boundary; or

b.  An abrupt textural change between the eluvial horizon and the upper boundary of the argillic horizon; or

2.  An argillic horizon that extends to 150 cm or more from the soil surface, that does not have a clay decrease with increasing depth of 20 percent or more (relative) from the maximum clay content, and that has, in 50 percent or more of the matrix in some part between 100 and 150 cm, either:

and value, dry, of 4 or less.

Paleargids, p. 114

GED.  OtherArgids that have a gypsic horizon within 150 cm of the soil surface.

Gypsiargids, p. 109

GEE.  OtherArgids that have a calcic horizon within 150 cm of the soil surface.

Calciargids, p. 107

GEF.  OtherArgids.

Haplargids, p. 110

Calciargids

Key to Subgroups

GEEA.  Calciargids that have a lithic contact within 50 cm of the soil surface.

Lithic Calciargids

GEEB.  Other Calciargids that have both: 1.  One or both of the following:

a.  Cracks within 125 cm of the soil surface that are 5 mm or more wide through a thickness of 30 cm or more

A R I

for some time in normal years and slickensides or wedgeshaped peds in a layer 15 cm or more thick that has its upper boundary within 125 cm of the soil surface; or

b.  Alinear extensibility of 6.0 cm or more between the soil surface and either a depth of 100 cm or a densic, lithic, or paralithic contact if shallower; and

2.  A moisture control section that, in normal years, is dry in all parts for less than three-fourths of the time (cumulative) when the soil temperature at a depth of 50 cm below the

soil surface is 5 oC or higher and a soil moisture regime that borders on xeric.

Xerertic Calciargids

GEEC.  Other Calciargids that have both: 1.  One or both of the following:

a.  Cracks within 125 cm of the soil surface that are 5 mm or more wide through a thickness of 30 cm or more for some time in normal years and slickensides or wedgeshaped peds in a layer 15 cm or more thick that has its upper boundary within 125 cm of the soil surface; or

b.  Alinear extensibility of 6.0 cm or more between the soil surface and either a depth of 100 cm or a densic, lithic, or paralithic contact if shallower; and

2.  A moisture control section that, in normal years, is dry in all parts for less than three-fourths of the time (cumulative) when the soil temperature at a depth of 50 cm below the

soil surface is 5 oC or higher and a soil moisture regime that borders on ustic.

Ustertic Calciargids

GEED.  Other Calciargids that have one or both of the following:

1.  Cracks within 125 cm of the soil surface that are 5 mm or more wide through a thickness of 30 cm or more for some time in normal years and slickensides or wedge-shaped peds in a layer 15 cm or more thick that has its upper boundary within 125 cm of the soil surface; or

2.  Alinear extensibility of 6.0 cm or more between the soil surface and either a depth of 100 cm or a densic, lithic, or paralithic contact if shallower.

Vertic Calciargids

GEEE.  Other Calciargids that are either:

1.  Irrigated and have aquic conditions for some time in normal years in one or more layers within 100 cm of the soil surface; or

2.  Saturated with water in one or more layers within 100 cm of the soil surface for 1 month or more in normal years.

Aquic Calciargids

GEEF.  Other Calciargids that:

1.  Have a texture class (fine-earth fraction) of coarse sand, sand, fine sand, loamy coarse sand, loamy sand, or loamy fine sand throughout a layer extending from the soil surface to the top of an argillic horizon at a depth of 50 cm or more; and

2.  Have a moisture control section that, in normal years, is dry in all parts for less than three-fourths of the time

(cumulative) when the soil temperature at a depth of 50 cm below the soil surface is 5 oC or higher and a soil moisture regime that borders on ustic.

Arenic Ustic Calciargids

GEEG.  Other Calciargids that have a texture class (fine-earth fraction) of coarse sand, sand, fine sand, loamy coarse sand, loamy sand, or loamy fine sand throughout a layer extending from the soil surface to the top of an argillic horizon at a depth of 50 cm or more.

Arenic Calciargids

GEEH.  Other Calciargids that have both:

1.  One or more horizons, within 100 cm of the soil surface and with a combined thickness of 15 cm or more, that contain 20 percent or more (by volume) durinodes or are brittle and have at least a firm rupture-resistance class when moist; and

2.  A moisture control section that, in normal years, is dry in all parts for less than three-fourths of the time (cumulative) when the soil temperature at a depth of 50 cm below the

soil surface is 5 oC or higher and a soil moisture regime that borders on xeric.

Durinodic Xeric Calciargids

GEEI.  Other Calciargids that have one or more horizons, within 100 cm of the soil surface and with a combined thickness of 15 cm or more, that contain 20 percent or more (by volume) durinodes or are brittle and have at least a firm ruptureresistance class when moist.

Durinodic Calciargids

GEEJ.  Other Calciargids that have both:

1.  One or more horizons, within 100 cm of the soil surface and with a combined thickness of 15 cm or more, that contain 20 percent or more (by volume) nodules or concretions; and

2.  A moisture control section that, in normal years, is dry in all parts for less than three-fourths of the time (cumulative) when the soil temperature at a depth of 50 cm below the

soil surface is 5 oC or higher and a soil moisture regime that borders on xeric.

Petronodic Xeric Calciargids

GEEK.  Other Calciargids that have both:

1.  One or more horizons, within 100 cm of the soil surface and with a combined thickness of 15 cm or more, that contain 20 percent or more (by volume) nodules or concretions; and

2.  A moisture control section that, in normal years, is dry in all parts for less than three-fourths of the time (cumulative) when the soil temperature at a depth of 50 cm below the

soil surface is 5 oC or higher and a soil moisture regime that borders on ustic.

Petronodic Ustic Calciargids

GEEL.  Other Calciargids that have one or more horizons, within 100 cm of the soil surface and with a combined thickness of 15 cm or more, that contain 20 percent or more (by volume) nodules or concretions.

Petronodic Calciargids

GEEM.  Other Calciargids that have both:

1.  A moisture control section that, in normal years, is dry in all parts for less than three-fourths of the time (cumulative) when the soil temperature at a depth of 50 cm below the

soil surface is 5 oC or higher and a soil moisture regime that borders on xeric; and

2.  Throughout one or more horizons with a total thickness of 18 cm or more within 75 cm of the soil surface, one or both of the following:

horizons with a total thickness of 18 cm or more within 75 cm of the soil surface, one or both of the following:

1.  More than 35 percent (by volume) particles 2.0 mm or larger in diameter, of which more than 66 percent is cinders, pumice, and pumicelike fragments; or

2.  Afine-earth fraction containing 30 percent or more particles 0.02 to 2.0 mm in diameter, of which 5 percent or more is volcanic glass, and [(Al plus 1/2 Fe, percent extracted by ammonium oxalate) times 60] plus the volcanic glass

(percent) is 30 or more.

Vitrandic Calciargids

Key to Subgroups

GEDA.  Gypsiargids that are either:

1.  Irrigated and have aquic conditions for some time in normal years in one or more layers within 100 cm of the soil surface; or

2.  Are saturated with water in one or more layers within 100 cm of the soil surface for 1 month or more in normal years.

Aquic Gypsiargids

GEDB.  Other Gypsiargids that have one or more horizons, within 100 cm of the soil surface and with a combined thickness of 15 cm or more, that either contain 20 percent or more (by volume) durinodes or are brittle and have at least a firm ruptureresistance class when moist.

Durinodic Gypsiargids

GEDC.  Other Gypsiargids that have both:

1.  A moisture control section that, in normal years, is dry in all parts for less than three-fourths of the time (cumulative) when the soil temperature at a depth of 50 cm below the

soil surface is 5 oC or higher and a soil moisture regime that borders on xeric; and

2.  Throughout one or more horizons with a total thickness of 18 cm or more within 75 cm of the soil surface, one or both of the following:

a.  More than 35 percent (by volume) particles 2.0 mm or larger in diameter, of which more than 66 percent is cinders, pumice, and pumicelike fragments; or

b.  Afine-earth fraction containing 30 percent or more particles 0.02 to 2.0 mm in diameter, of which 5 percent

or more is volcanic glass, and [(Al plus 1/2 Fe, percent extracted by ammonium oxalate) times 60] plus the volcanic glass (percent) is 30 or more.

Vitrixerandic Gypsiargids

GEDD.  Other Gypsiargids that have, throughout one or more horizons with a total thickness of 18 cm or more within 75 cm of the soil surface, one or both of the following:

1.  More than 35 percent (by volume) particles 2.0 mm or larger in diameter, of which more than 66 percent is cinders, pumice, and pumicelike fragments; or

2.  Afine-earth fraction containing 30 percent or more particles 0.02 to 2.0 mm in diameter, of which 5 percent or more is volcanic glass, and [(Al plus 1/2 Fe, percent extracted by ammonium oxalate) times 60] plus the volcanic glass

(percent) is 30 or more.

Vitrandic Gypsiargids

GEDE.  Other Gypsiargids that, in normal years, are dry in all parts of the moisture control section for less than three-fourths of the time (cumulative) when the soil temperature at a depth of 50 cm below the soil surface is 5 oC or higher and have a soil moisture regime that borders on xeric.

Xeric Gypsiargids

GEDF.  Other Gypsiargids that, in normal years, are dry in all parts of the moisture control section for less than three-fourths of the time (cumulative) when the soil temperature at a depth of 50 cm below the soil surface is 5 oC or higher and have a soil moisture regime that borders on ustic.

Ustic Gypsiargids

GEDG.  Other Gypsiargids.

Typic Gypsiargids

Haplargids

Key to Subgroups

GEFA.  Haplargids that have both:

1.  A lithic contact within 50 cm of the soil surface; and

2.  An argillic horizon that is discontinuous throughout each pedon.

Lithic Ruptic-Entic Haplargids

GEFB.  Other Haplargids that have both:

1.  A lithic contact within 50 cm of the soil surface; and

2.  A moisture control section that, in normal years, is dry in all parts for less than three-fourths of the time (cumulative) when the soil temperature at a depth of 50 cm below the

soil surface is 5 oC or higher and a soil moisture regime that borders on xeric.

Lithic Xeric Haplargids

GEFC.  Other Haplargids that have both:

1.  A lithic contact within 50 cm of the soil surface; and

2.  A moisture control section that, in normal years, is dry in all parts for less than three-fourths of the time (cumulative) when the soil temperature at a depth of 50 cm below the

soil surface is 5 oC or higher and a soil moisture regime that borders on ustic.

Lithic Ustic Haplargids

GEFD.  Other Haplargids that have a lithic contact within 50 cm of the soil surface.

Lithic Haplargids

GEFE.  Other Haplargids that have both: 1.  One or both of the following:

a.  Cracks within 125 cm of the soil surface that are 5 mm or more wide through a thickness of 30 cm or more for some time in normal years and slickensides or wedgeshaped peds in a layer 15 cm or more thick that has its upper boundary within 125 cm of the soil surface; or

b.  Alinear extensibility of 6.0 cm or more between the soil surface and either a depth of 100 cm or a densic, lithic, or paralithic contact if shallower; and

2.  A moisture control section that, in normal years, is dry in all parts for less than three-fourths of the time (cumulative) when the soil temperature at a depth of 50 cm below the

soil surface is 5 oC or higher and a soil moisture regime that borders on xeric.

Xerertic Haplargids

GEFF.  Other Haplargids that have both: 1.  One or both of the following:

a.  Cracks within 125 cm of the soil surface that are 5 mm or more wide through a thickness of 30 cm or

more for some time in normal years and slickensides or wedge-shaped peds in a layer 15 cm or more thick that has its upper boundary within 125 cm of the soil surface; or

b.  Alinear extensibility of 6.0 cm or more between the soil surface and either a depth of 100 cm or a densic, lithic, or paralithic contact if shallower; and

2.  A moisture control section that, in normal years, is dry in all parts for less than three-fourths of the time (cumulative) when the soil temperature at a depth of 50 cm below the